Since its discovery, graphene has been a highly investigated material across a wide range of research fields. Its exceptional properties, such as electrical conductivity of up to 104 S/cm, elastic modulus of up to 1 TPa, and surface area of over 2500 m2/g have inspired applications in electronics, conductive composites, catalysis, photovoltaics, energy storage, and biology. Recent efforts to build three-dimensional (3D) architectures of graphene have demonstrated significantly enhanced performance due to increased active material per projected area. Several methods have been proposed for building 3D graphene, including chemical vapor deposition (CVD), colloidal gelation, sol-gel, and graphene oxide (GO)-based gelation. While CVD is the most common method for high quality two-dimensional (2D) graphene film growth, 3D graphene structures available via CVD are macroporous foams due to limitations imposed by the requirement for growth on a metal support. As a consequence, chemically derived GO-based graphene aerogels are the most common 3D graphene found in the literature due to their simple and versatile fabrication process and the ability to realize a wide range of pore morphologies, including ultrafine pore sizes (<100 nm). The ultrafine pore sizes in aerogels are a key advantage over macroporous foams in a number of applications. For example, small pores have shown enhanced capacitance relative to larger pores, leading to performance enhancements in supercapacitor and capacitive desalination applications. Similarly, the small pore sizes and high surface areas in aerogels have also proved advantageous in technologies, such as hydrogen storage, catalysis, batteries, filtration, insulation, and sorbents. In general, the GO-based graphene aerogels are formed by inducing the gelation of an aqueous GO suspension, such that the GO is partially reduced and forms a porous 3D network within the fluid. Upon removal of the fluid phase via critical point drying (or freeze-drying), the dry 3D graphene emerges. However, the quality of the graphene sheets in these chemically derived graphene aerogels is less favorable compared to the graphene produced via mechanical exfoliation or CVD. This translates to macroscale bulk properties, such as electrical conductivity, that are less favorable than those of CVD-grown 3D graphene used in conductive polymer composites.
Therefore, a need exists for improving the quality of chemically derived graphene aerogels.